1580s, in reference to lines of verse of a particular construction, from Middle French élégiaque, from Latin elegiacus, from Greek elegeiakos, from eleigeia (see elegy). In ancient Greece the verse form was used especially with mournful music. Meaning "pertaining to an elegy or elegies" is from 1640s in English; loosened sense "expressing sorrow, lamenting" is from c.1800. Related: Elegiacal (1540s, of meter); elegiacally.